In order to treat a diseased liver, such as a cancerous liver, drugs can be directly dispensed into the target tissue. Since vascularisation in the liver is high, many vessels (e.g., blood vessels) pass through the liver. As a result, substances fed to the liver often outflow from the liver to other parts of the body.
Techniques exist for influencing the perfusion of hepatic tissue. If perfusion in the tissue can be reduced, the retention period of the administered substance within the liver can be extended, and the therapeutic effect can be correspondingly improved, while simultaneously diminishing side-effects.
For treating liver cancer, a technique called transarterial chemoembolisation (TACE) is known, wherein the blood supply to a tumor is interrupted and chemotherapy is administered directly on the tumor. The chemotherapeutic agents, for example, can be injected into the hepatic artery leading to the hepatoma. In chemoembolisation, additional material may be injected to block small branches of the hepatic artery. It is very likely, however, that a considerable portion of the chemotherapeutic agents will enter other parts of the body. Selective intra-arterial chemotherapy can therefore cause the usual systematic side-effects that affect the entire body. This treatment also can lead to a number of side-effects that regionally affect particular parts of the body, such as, for example, inflammation of the gallbladder (cholecystitis), intestinal or stomach ulcers and inflammation of the pancreas (pancreatitis). Liver failure also can occur after such treatment in patients with hepatocellular carcinoma (HCC) and advanced cirrhosis.
Other methods for treating the liver include attaching radioactive material to antibodies that are directed at particular target areas in liver cancer cells (immunotherapy). A method and device for administering a substance is known from EP 1 316 324 A1 belonging to the Applicant.